Suspended Wooden Floor into concrete

[aaront]

I am about to lift the wooden floor in my kitchen for several good reasons:

- its uneven
- laying in new plumbing for a new rad
- cleaning out the underfloor space and checking for adequate ventilation
- replacing/strengthening the floor joists

on one side of the room the floor changes to concrete for approx 3 feet up to the external wall.

This external wall has some rising damp all along it. The external ground level also appears to be above the dpc so i will be dropping that.

My question is - should I dig out the concrete? Its very cracked and underneath will pretty much come out by hand. If I dig it all out to the level beneath the wooden floor (approx 18") and put a couple of new joists in with a couple of vent bricks in the external wall will I eradicate the damp? Is it worth the effort?

Any feedback is appreciated.

 

[masona]

Was this concrete a old fireplace? If so this does tend to give damp problem if not being use and it will be worth it to take it down to the oversite as much as you can so you get proper air-vent crossflow.All gound level should be at least 150mm below dpc

 

[DAZB]

You may be best checking that the concrete does not form some part of the footing for the external wall. If you go through the concrete close to the wall with a long drill bit you will be able to determine the thickness of the slab. If it is over 4 inch deep then it may be there for a reason. I would imagine the damp on your wall will be due to the external ground level being above the DPC and therefore the moisture is just tranfering across from outside to inside.If you find the slab is removable then your plan above sound like a good one and should solve the damp.

 

[aaront]

The concrete is not a part of the footings. The top later is 2-3" thick and loose in most places. Like I say it will easily dig out with a shovel once the top player has come away. Its not a part of a fireplace, there is one in a different part of the room which i have already dug out.